Forming the profile of complex surfaces in manufacturing environments is a time consuming, expensive, labor intensive operation. Unfortunately, it is often an indispensable part of the manufacturing process. Most often surface profiling is done point by point using contact measuring devices. The major advantage of such techniques is that by using a variety of measuring devices any desired dimension can be found, even on the most complex parts. The major disadvantages are long measurement times and the fact that mechanical contact must be made with sometimes fragile or deformable parts. To overcome these difficulties various optical concepts have been tried. None of these schemes has found widespread acceptance, due primarily to the limited number of surface types each can accommodate, as well as the point by point data reduction required by the non-automated techniques. Another problem encountered by all optical techniques is shadowing caused by protruding features or steep edges on the object. This shadowing makes it necessary to use multiple views in order to contour the whole surface.
Accordingly, there is a need for an automated, optical surface profiling instrument capable of measuring a wide variety of surfaces while minimizing the shadowing problem.